Question

1. a weightlifter is using heavy weights in short bursts for a competition. *0/2 because his muscle cells are not able to take in enough oxygen to make very much atp the weightlifter begins to get fatigue in his muscles. which of the following processes is most likely going on in the muscles of the weightlifter as he competes in his event? a. as the cells run out of oxygen they switch to anaerobic respiration, which allows the cell to make small amounts of atp in the absence of oxygen. b. as the cells run out of oxygen, they die off gradually and the weightlifters muscles have fewer contracting muscle cells. c. the cells will never run out of oxygen if the weightlifter is breathing. d. as the cells run out of oxygen, they will continue to make the same amount of atp, since oxygen is not required to make atp.

Explanation:

• Option A: When oxygen is limited (as in the weightlifter's muscles during intense, short - burst activity), cells switch to anaerobic respiration. Anaerobic respiration (like lactic acid fermentation in humans) produces a small amount of ATP compared to aerobic respiration. This is a valid biological process.
• Option B: Cells do not "die off gradually" just because oxygen is limited in a short - term, high - intensity activity like weightlifting. Muscle fatigue due to oxygen limitation is related to metabolic changes (like lactic acid build - up from anaerobic respiration), not cell death.
• Option C: Just because the weightlifter is breathing does not mean the cells in the working muscles (which have high energy demands) have an unlimited supply of oxygen. The rate of oxygen consumption by the muscle cells during intense activity can exceed the rate of oxygen delivery.
• Option D: Oxygen is required for aerobic respiration, which is the most efficient way to produce ATP. While there are anaerobic processes to produce ATP, they produce much less ATP than aerobic respiration. So, the amount of ATP produced changes when oxygen is limited.

Answer:

A. As the cells run out of oxygen they switch to anaerobic respiration, which allows the cell to make small amounts of ATP in the absence of oxygen.